CVE-2026-41429: CWE-121: Stack-based Buffer Overflow in espressif arduino-esp32
A stack-based buffer overflow vulnerability exists in the arduino-esp32 core for Espressif microcontrollers prior to version 3. 3. 8. The issue occurs in the NBNS packet handling path when NetBIOS is enabled, allowing an attacker on the local network to send malicious NBNS requests that exploit an unchecked name length field. This can lead to memory corruption with potential for high impact on confidentiality, integrity, and availability. The vulnerability is fixed in version 3. 3. 8.
AI Analysis
Technical Summary
The arduino-esp32 core for ESP32 series microcontrollers has a stack-based buffer overflow (CWE-121) in its NBNS packet parser. When NetBIOS is enabled via NBNS.begin(...), the device listens on UDP port 137 and processes NBNS requests from the local network. The parser does not properly validate the attacker-controlled name_len field against fixed-size buffers, leading to memory corruption. This vulnerability is remotely reachable within the local network and affects versions prior to 3.3.8. A patch fixing this issue is available in version 3.3.8.
Potential Impact
Successful exploitation can result in memory corruption that compromises confidentiality, integrity, and availability of the affected device. Given the CVSS score of 8.8 with network attack vector and no privileges required, the vulnerability poses a high risk to devices running vulnerable versions with NetBIOS enabled. There are no known exploits in the wild at this time.
Mitigation Recommendations
A fix is available in arduino-esp32 version 3.3.8. Users should upgrade to version 3.3.8 or later to remediate this vulnerability. Since this is a cloud-managed service, the vendor manages remediation for the cloud-hosted components; however, for on-premises or embedded deployments, manual upgrade is required. No additional mitigation steps are indicated by the vendor advisory.
CVE-2026-41429: CWE-121: Stack-based Buffer Overflow in espressif arduino-esp32
Description
A stack-based buffer overflow vulnerability exists in the arduino-esp32 core for Espressif microcontrollers prior to version 3. 3. 8. The issue occurs in the NBNS packet handling path when NetBIOS is enabled, allowing an attacker on the local network to send malicious NBNS requests that exploit an unchecked name length field. This can lead to memory corruption with potential for high impact on confidentiality, integrity, and availability. The vulnerability is fixed in version 3. 3. 8.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The arduino-esp32 core for ESP32 series microcontrollers has a stack-based buffer overflow (CWE-121) in its NBNS packet parser. When NetBIOS is enabled via NBNS.begin(...), the device listens on UDP port 137 and processes NBNS requests from the local network. The parser does not properly validate the attacker-controlled name_len field against fixed-size buffers, leading to memory corruption. This vulnerability is remotely reachable within the local network and affects versions prior to 3.3.8. A patch fixing this issue is available in version 3.3.8.
Potential Impact
Successful exploitation can result in memory corruption that compromises confidentiality, integrity, and availability of the affected device. Given the CVSS score of 8.8 with network attack vector and no privileges required, the vulnerability poses a high risk to devices running vulnerable versions with NetBIOS enabled. There are no known exploits in the wild at this time.
Mitigation Recommendations
A fix is available in arduino-esp32 version 3.3.8. Users should upgrade to version 3.3.8 or later to remediate this vulnerability. Since this is a cloud-managed service, the vendor manages remediation for the cloud-hosted components; however, for on-premises or embedded deployments, manual upgrade is required. No additional mitigation steps are indicated by the vendor advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-20T15:32:33.814Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
- Is Cloud Service
- true
Threat ID: 69ebeffb87115cfb687b9d71
Added to database: 4/24/2026, 10:34:35 PM
Last enriched: 4/24/2026, 10:34:42 PM
Last updated: 4/25/2026, 12:44:10 AM
Views: 6
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